Lubricating oil additive



. the patent to Roelen,

' Patented Sept. 30, 1952 LUBRICATING OIL ADDITIVE Jeffrey H. Bartlett, Westfield, N. J assignor to f. Standard 011 Development Company, a corporation of Delaware Serial No. 124,255

" No Drawing. Application October 28, 1949,

6 Claims.

This invention relates to novel and useful products formed by the polymerization of aryl acrylic acid esters. The invention also relates to copolymers of aryl acrylic acid esters withother polymerizable unsaturated materials. More particularly, the invention relates to polymers of a substituted or unsubstituted cinnamicacid ester in which the ester portion of the molecule con- I tains a carbon chain having from 8 to 22 carbon atoms. The invention also relates particularly to lubricating oil compositions containing a minor proportion of these novel'polymers and copolymers.

The novel polymers and copolymers which form the subject of. this invention are useful for many purposes. They reduce the pour point of lubricating oils when blended therein in certain percentages, they are useful for improving the viscosity index of oils into which they are blended, and they are useful as oiliness agents. In general the overall engine conditions are improved when a blend of these materials and lubricating oil is used. However their particular advantage is in their use as pour depressants and viscosity index improvers. w

One aspect of the invention comprises polymerizing an aryl acrylic acid ester having the general formula 1 f R Wherein R represents the alcohol contributed portion of the ester and is derived from primary straight chain alcohols having a carbon chain length of from 8 to 22 carbon atoms and B may be hydrogen, chlorine or a methyl group. Although ester groups containing from 8 to 22 carbon atoms are operable, carbon chains having from 10 to 20 carbon atoms are preferred. Secondary and branched chain alcohols may also be used to furnish the alcohol contributed portion.

It is also within the concept of this invention to utili'ze the so-called Oxo-alcohols in the esterification. These alcohols areformed by the hydrogenation of the reaction product obtained when an olefin is subjected to the action of carbon monoxide and hydrogen in the presence of a catalyst according to the procedure outlined in U. 8. Patent 2,327,066.

Polymers and copolymers of-olefins such as ethyl- 2 ene, propylene, 'butylene, amylene, etc. may b subjected to the Ox-synthesis. process, resulting in a primary alcohol having one more carbon atom than the starting olefin.

Although the alcohols used in this esterification may be either saturated or unsaturated, saturated alcohols are preferred.

Some commercially available mixedalcohols which are especially suitable for use inthis invention are products obtained by the hydrogena: tion of coconut oil. Such products are sold under the trade nam -Lorol and are mixtures of saturated straight chainalcoholshaving the following approximate composition:

Percent of- Lorol Lorol B Lorol R Cm 4. 0 3. 0 l. 0 C12 :55- 5 46. 0 85. 0 C14- 22. 5 24. O 13. 0 01a 14.0- 10.0 1.0 Cu; .450 17.0 0.0 Ave. chain length I 12. 8 13. 5 12.2

Among the aryl acrylic iacidsawliich. mar be used in the formulation of the esters operable in this invention may be mentioned einnamic acid,

and its chloro and methyl derivatives, such, as

.acid, beta-(3,5 dimethylphenyl) acrylic acid,

beta-(2,4,5-trimethylphenyl) acrylic acid, etc. Although any of the above listed-substituted or unsubstituted aryl' acrylic acids may be used,

cinnamic acid is the preferred embodiment of the invention. 7 r e l I The technique used in the polymerization of these aryl acrylic acid esters maybe either-the emulsion or the bulk polymerization technique using a peroxide-type .cataly'st,;-such as benzoyl peroxide, urea hydroperoxide, cumene liydroperoxide, tertiary butyl hydroperoxidewand the like. The. redox type polymerization technique, whereby the polymerization reaction is activated. by

1 the presence of both oxidizing andreducing agents, may also beused. 1

The polymerization-iscarri d out in the absence of air at a ;temperature,offrom about 25 I be weak in'p'our depressant properties. I 'viscosity index improving properties are desired,

mers.

a period of time of from about 2 to about 100 I hours, preferably to 20 hours. The polymerization should be carried out for a sufiicient period of time and at a sufficient temperature to give a product having a molecular weight within a range of from about 1,000 to about 40,000 Staudinger. Polymers having a molecular weight below about 1,000 are generally found to Where polymers having molecular weights in the range of from 5,000 to 25,000, especially 10,000 to 1 20,000, are preferred sincethey have. good V. I;

potency and also are more resistant to shear breakdown than higher molecular Depending upon the characteristics desired to weight poly- 4 pour depressant tests. The results of these tests are given in Table I below:

Table I 5 A. S. T. M. POUR POINT TESTS CINNAMATE ESTER POLYMERS Polymer Pour Points of Base Stock Blends 1o Y in. I v

No. ggf g on A 1 011B 0110 1 tration F. +20 F. +30 F F. -15 F. 5 F. +5 F 15 F. +5 F. +5 F 0 F. F.

be utilized, these polymers are blended 'with lubricating oils in varying proportions. For example, when it is desired to blend a lubricating H composition having a desirable lowered pour point, the polymer products of this invention are usedfin concentration varying from about 0.05 to 5.0 weight percent. When it is desired to impart improved viscosity temperature relationships to the lubricating oil blend, higher percentages of the polymer are preferred, from 1.0 to 15.0 weight per cent being used. The

lubricating oil with whichfthe'se polymers may be blended may be either natural occurring mineral base lubricating oils of a paraffinic or naphthe'nic nature or the base stocks 'may be "of the synthetic type,;s'u'ch as esters of diacids such asgs'eba'cates, long chain esters, polymerized cracked wax, falkylated aromatics, pol'yglyools, etc.

The invention may be further described by means of the following examples in which various of the esters of an aryl acrylic acid were polymerized. V EXAMPLE I PA x 200 millimeter test tube was charged with grams of Lorol B cinnamat'e. After heating to about 60 C. the air was displaced with nitrogen and 1.5 grams of benzoyl peroxide were added. fIhis mixture'was-genuy blown with .nitrogen jii'ntil'mofs't or the peroxide had dissolved. The test tube was then loosely stoppered amp aeea in an"o v'en*at-80 C. fo'r' 90 hours and a fp oly'jmer resulted whichha-d a viscosity at 2 10? Fr. of 74.9 s.-U. s.). v

7 EXAMPLE II ,A polymerization reaction similar to that described in Example I was carried out using tetradecyl einnamate in the place of the Lorol B cinnamate of Example I. The polymerization was continued for 16 hours-at 60C. and-for 58 hours at 80 C. "A polymer resulted which had a viscosity at 210 F. of 401 S. U. S.

EXAMPLE III A polymerization similar 'to that described in Example I was'carried out using cetylci'nnamate instead of the Lorol B cinnamate of Example 1. After a polymerization-reaction of 16 hours at 60 C. and 58 hours at'80-C. apoymer resulted which had a viscosityat 210 F. of 166'Saybo1t seconds. v I The polymers formed according 'torthe procedures described above were blendedwith'three lubricating oil base stocks "and "tested for pour depressant potency'according to the A. S. TQM.

h conventionally refih'edPennsylvania neutral having a viscosity at 210 .-F. of 45.3 S. U..S and a V. I. of 100.

- 2 A solvent extracted M-id-Oontinent neutral-bright stock blend having a viscosity at 210 F. 01' 46.1 S. U. S. and a V. I. of 103 3 A solvent extracted Mid-Continent neutral-bright stock blend havingaviscosity at 210 F. of 43.6 S. U. S. and a V. I. of 95.

It will be noted by examination of the data givenin Table I above that the novel-polymers of this invention-showed pour poih't depressing efiect's' all of thefthr'ee types b'f'basebils ith which they were blended-reducingtlrefpou pint of the blend as much as 35 the ease or polymer II in 0113.

In-addition'to' the pmyme which may be preparedfror'n esters bfan aryi acrylic acid, whether substituted or unsubstituted, 11 151518 also been found, and forms a *secoiid aspect of this n: vention, that eo'poiy rs *or' th'ese t'e'i s with other polymerizable unsaturated materials have pour depressant potency. The unsaturatedterials contemplated for eopoiymerization with the estersjoftlie aryl yup-a ds as described above, aresuch' mate alfs a's tli esters-or the I unsaturated materials mentioned above are oper- Sat/bolt iiniversai seconds able and within the concept of thrsinventiomit is preferred to copolyrjrierize an arylaerylic acid with a compound such as theesters "of acrylic and methacrylic acids, the methyl esters being especially preferred.

The conditions for the copoly-merization are substantially the same'as those described above for the polymerization reaction.

Various copolymers of the type mentioned abovewere prepared-according :to the following procedure. l; L. 1 I

A cop'olymeri-zati'on reaotio'n wasi carried out under conditions similar tdthos'ef described in Example I inwhich2'4 grains of 'c'etyl oir'marnate and 6 gramslofmethyl acryl'ate were copolymerized in the ilpreseiice of 0.5 Tgrain ,oi benzoyi peroxide-at 60 CIiorl5lioiii's. v n

1 A 'co'polymerization *similar; to thatI-I-desc'ribed in Example IV :was earriedout substituting 32 grams of octadecyl' cinnamate; for thewcetyl cinna'mate'of Example-IV. -Eightrgrams of methyl acrylate were-jusedand 0.-4.-g:ram-of :benzoyl cosity rof .210 Ffof 27-95 Saybolt'seconds.

5 'EXAMPLE'VI j A copolymerization similar to that described ,in Example IV was carried-out using 321grams of tetradecylcinnamate and 8 grams of vinyl acetate with 2 grams of benzoyl peroxide- The polymerization was carried on for 16 hours'at 60 C. and 58 hours at80 C. and yieldeda copolymer having a viscosity at'210 F. of 113 Saybolt seconds. C

The copolymers formed in accordance with Examples IV, V, and VI above were blended with three diifere'nt types or lubricating oil base stocks and tested for pour point reduction according to the A. S. T. M. pour point test. The result s,

of these tests'are given in Table II below:

Table '11 A. S. '1. M. IOUR POINT TESTS OINNAMATE ESTER OOPOLYMERS Polymer Pour Points of Base Stock Blends Wt. v No. 532%; on A I Oil B on c tration 10" F +20 F +30" F. 0' F -l 0 F F. +5 F 0 F F. 0 F F I 0 F.

to lubricating oil blends containing minor propor- I tions of the polymer or copolymer products.

It is to be understood, of course, thatthese lubricating oil additives do not prohibit the addition of various other lubricating oil additives'to blends in which they are used. For example, they are completely compatible with oxidation inhibitors, sludge dispersers, detergents, corrosion inof time of from-"about 5 to";about ZQ fhOUI'S in "the 3 presence be a peroxidetypecatalyst "and in "wherein 1R. r prese ted alkyi I from 10'-*to-20 carbon atoms, tea-temperature 5.0% loy -weightizof a .homopoly'meric .1 material prepared subjecting a. (compound; of; the gen- '-':ia.'1*-formula;: 1: 4 '1 v g, 7 group containing of from about 40 w about 100 C. for a period "the'absenceof air.

3. A lubricating oil compositionwhi'ch comprises ing oil base stock having combined therein about 0.2 to about 5.0% by weight of a homopolymeric material formed by subjecting a cinnamic acid ester in which the alcohol contributed portion this invention comprises the hibitors, other viscosity index improvers, pour depressors and the like.

What is claimed is:-

1. A lubricating oil composition which comprises a major proportion of a mineral lubricating oil base stock having combined therein a minor proportion sufficient to reduce the pour point thereof of a homopolymeric material formed by subjecting a compound having the general formula:

CH=CHC/ 100 hours in the absence of air and in the presence of a peroxide type catalyst.

2. A lubricating oil composition which comprises a major proportion of a mineral lubricating oil having combined therein from 0.05 to of the ester comprises a mixture of hydrogenated coconut oil alcohols having an average chain length of about 13.5 carbon atoms, to a temperature of about C. for about hours in the absence of air and in the presence of a benzoyl peroxide catalyst.

v 4. A lubricating oilcomposition which comprises a major proportion of amineral lubricating oil base stock having combined vtherein a minor proportion sufiicient to reduce the pour point thereof of a copolymeric material formed by subjecting about 4 parts by weight of a compound having the general formula:

CH=OHC/ wherein R is an alkyl group containing from 8 to 22 carbon atoms and R is selected from the class consisting of hydrogen, chlorine and methyl groups with about 1 part by weight of a com- 7 groups, to a temperature of about 25 to about 150 C. for a period of time of from about 2 to about hours in the absence of air and in the presence of a peroxide type catalyst.

5. A lubricating oil composition which comprises a major proportion of a mineral lubricating oil base stock having combined therein from about 0.05% to about 5.0% by weight. of a copolymeric material formed by subjecting about 4 parts by weight of a compound having the general formula:

wherein R represents an alkyl roup containing from 10 to 20 carbon atoms with about one part by weight ofa compound of the general formula:

- o cHFoH c a'major proportion of a mineral lubricat- V. absenceofvair.

itdfcfrom about glfiztocabontidoM16; for-:19; neriod of-time on from-about 6 tmabouwzozhoursrimthe presence of a peroxide-type catalystwndfsinzthe absence of air.

6. A lubricating oil composition which com :5

mille -pf-this,:patent: I v I I JQUNIIEDZSTATESTPATENTS1.. prises a major proportion of a mineral lubricat- E Nnmber v ing oil base stock having con'ibin'ed therein about "33 2 0714 0.2% toabout 5.0 by--weight.of. a copolymeric 2. 912627 material forme'd bysubjecting zabout 4 mar-ts 2, 1 by weighuur -cety1 cinnamate with a'boutdapart 10 V 0, 4 by w'eight of: methylacrylatet at 1a-temperaturel of T' ;411' ;1

about 60 C.-in-- the.. presence of wabout flfiqgram 32242 28523 of benzoj l peroxide for aboutz-lsflhoursiin. the "121 9227 REFERENQESYEITED The-following references are of recordin the 

1. A LUBRICATING OIL COMPOSITION WHICH COMPRISES A MAJOR PROPORTION OF A MINERAL LUBRICATING OIL BASE STOCK HAVING COMBINED THEREIN A MINOR PROPORTION SUFFICIENT TO REDUCE THE POUR POINT THEREOF OF A HOMOPOLYMERIC MATERIAL FORMED BY SUBJECTING A COMPOUND HAVING THE GENERAL FORMULA 